Looking into Space Flashcards
Why is it hard to study other stars and galaxies?
Because they are so far away
What can we do to study distant stars and galaxies?
Study the electromagnetic radiation that is emitted from them
What does emitted mean?
given off
Give examples of electromagnetic radiation
radio waves microwaves infra red visible light ultra violet x rays gamma rays
What does the colour of a star give a good indication of?
its surface temperature
How do scientists calculate the distance of ‘nearby’ stars?
They use a parallax
What is meant by a parallax
The distance that an object appears to move when you look at it from different points. (hold out your thumb and look at it from different eyes - see how it appears to move?)
What does the brightness of a star give an indication of?
The brightness is one way of getting an idea of the distance of a star
What causes problems when we are trying to look at stars from Earth?
the atmosphere and light pollution from streetlamps etc.
Why does the atmosphere make it difficult to see stars?
The light from the stars is absorbed by our atmosphere before it reaches our eyes so stars are difficult to detect
How have humans overcome the problems caused by the atmosphere and light pollution when trying to see stars?
They have launched the Hubble Space Telescope
How fast does light travel?
300 000 km/s
How long does it take the light from the Sun to reach us on Earth?
8 minutes
If the Earth exploded, how long would it take us to notice?
8 minutes after it actually happened because the light needs to reach our eyes
How far away is the nearest star to our star?
4.2 light years away
